Television sketching apparatus



Nov. 28, 1933. J. H. HAMMOND, JR

TELEVISION SKETCHING APPARATUS Filed May 11, 1929 TT RNEY Patented Nov. 28, 1933 PATENT GFFECE TELEVISION SKETCHING APPARATUS Johnllays Hammond, Jr., Gloucester, Mass.

Application May 11, 1929. Serial No. 362,233

1 Claim.

The invention relates in general to the art of communication, and more particularly, to the art of transmitting pictures.

According to the invention a television pick-up apparatus is provided for picking up an actual scene and transmitting the picture to a distance where suitable recording apparatus is provided for making a permanent record of the picked-up picture.

According to one form of the invention the pick-up apparatus may include a rotating disk having a series of spirally arranged holes for scanning the scene to be transmitted, together with suitable means for transforming the scanned light of'the picture into electrical energy. The

receiver on the other hand may comprise a rotating drum having also an axial movement, together with a device for making marks on the drum, which vary inv intensity with the trans- I mitted electrical energy. Suitable devices may also be provided for properly synchronizing the television pick-up apparatus and the picture recording apparatus.

The invention also consists in certain new and original features of construction and combinations of parts hereinafter set forth and claimed.

Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claim appended hereto, the invention itself, as to its objects and advantages, the mode of its operation and the manner of its organization may be better understood by referring to the following description taken in connection with the accompanying drawing forming a part thereof, in which Fig. l is a side elevation of the pick-up system;

Fig. 2 is a section taken on line 2-2 of Fig. 1; and

Fig. 3 is a plan View of the sketching apparatus at the receiving end.

In the following description and in the claim parts will be identified by specific names for convenience, but they are intended to be as generic in their application to similar parts as the art will permit.

Like reference characters denote like parts in the several figures of the drawing.

In the drawing accompanying and forming part of this specification, a practical commercial embodiment of the invention is shown, but as such illustration is primarily for purposes of disclosure, it will be understood that the structure may be modified in various respects without departure from the broad spirit and scope of the invention as hereinafter defined and claimed.

Referring to the drawing more in detail, Figs. 1 and 2 show a transmitting unit comprising a motor 10 mounted on a base 11. Secured to the shaft of the motor 1D is a Worm 12 which meshes with a worm wheel 13. This wheel is secured to a shaft 14 which has hearings in four brackets 15, 16, 17 and 18. Pinned to the 14 is a scanning circular disc 21 which is provided with a plurality of holes 22 laid out on a spiral as in Fig. 2. Carried by the bracket 18 is a plate 23 provided with a rectangular opening 24. Mounted in the bracket 17 is a lens 25, behind which is adjustably mounted a photo-electric cell 26. In front of the disc 21 is mounted a lens system 27 and in front of said lens system is placed the image to be transmitted.

The sketching or receiving apparatus consists of a motor 31 on the shaft of which is pinned a beveled gear 32, which meshes with a second beveled gear 33. This gear 33 is loosely mounted on a threaded shaft 34 and is provided with a key (not shown), which slides in a keyway 35 provided in the threaded shaft 34. The shaft 34 is threaded through a bearing 36. A second bearing 37 is provided for holding the gear 33 in place. The other end of the shaft 34 passes through a fixed bearing 38.

Mounted on the shaft 34 is a record receiving member such as drum 41, to which is secured a sheet of paper or other suitable material. Besting against the drum 41 isa pencil or other marker 42, which is carried by one end of a bell crank 43 and which is pivoted at 44. To the other end of the bell crank is secured one end of a spring 45, the other end of which is pivotally connected to an adjusting screw 46. This screw is threaded through a bracket 47. To the same end of the bell crank to which the spring 45 is attached is pivoted one end of a link 48, the other end of which is pivoted to a plunger 49 of a solenoid 51. This solenoid is connected conductors 52 and 53 to the output circuit of the receiver.

In the operation of this invention the motor 10 is run at a constant speed by any suitable means. This causes the disc 21 to run at a uni form speed. As it does so the holes 22 in this disc pass behind the opening 24 in the plate 23. This allows the light from the external scene which has been focused on the disc 21 by means of the lens 27 to pass through these holes as they come opposite the opening 24. The light then passes through the lens 25, which focuses it upon the photo-electric cell 26. The current from this cell is then amplified by any suitable means, and is transmitted either by wire or wireless to the receiver where it may be again amplified and fed to the conductors 52 and 53.

The motor 31 of the receiver is run at a uniform speed and is synchronized with the motor 10 at the transmitter. This drives the beveled gears 32 and 33, the latter one causing a rotation of the shaft 35, which rotate the drum 41. The motor 31 is so synchronized with the motor 10 that for every revolution of the scanning disc 21, the drum 41 rotates through as many revolutions as the number of apertures 22 disposed on said disc 21. The rotation of the threaded shaft 35 causes it to be fed through the threaded bearing 36 at a slow rate. This causes a gradual 1ongitudinal movement of the drum 41 until extreme position indicated by A (Fig. 3) is reached. This longitudinal movement of the drum 41 in combination with its rotation with the shaft 34 causes the surface of the drum to describe a helical course. As the drum 41 rotates the marker 42 presses against the paper an amount proportional to the current flowing through the solenoid 51, so that, the more current there is flowing through this solenoid, the harder the marker will be pressed against the paper, and the thickness of the line will be increased. In this way a reproduction of the scene at the transmitter is produced on the paper on the drum 41. The thickness of the line varies with the intensity of the light received by the photo-electric cell 26. By this means we obtain the sketch reproduced in strokes of varying width which correspond to the light and dark portions of the image and which form an excellent half tone likeness of the original image.

If desired, a suitable type of pen may replace the marker 42, and a sketch may thereby be made in ink.

While certain novel features of the invention have been shown and described and are pointed out in the annexed claim, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

In an apparatus of the character described, a solenoid responsive to pulsating currents, an armature plunger associated with said solenoid and adapted to be longitudinally displayed in response to variations in said currents, a bell crank lever with an arm thereof secured to said armature plunger, a marker mounted on the other arm of said bell crank lever, a spring secured to said bell crank lever, an adjusting screw affixed to said spring and adapted to adjust the tension thereof, a shaft with a threaded portion thereon, threaded bearings for engaging said threaded portion, a keyway on said shaft, a drum mounted on said shaft, the periphery of which engages said marker, a first gear loosely mounted on said shaft, a key mounted in said first gear and adapted to engage in said keyway, a motor, a second gear on said motor, said gear meshing with said first gear whereby the periphery of said drum is made to describe a helical course.

JOHN HAYS HAMMOND, JR. 

